Quantitative molecular ecology of phytoplankton viruses

浮游植物是水生环境的主要初级生产者，在水生食物网中起着重要作用，影响着全球化学循环。除了滋养绝大多数水生生物外，浮游植物还通过将大气中的二氧化碳转化为有机碳来清除大气中的二氧化碳；海洋浮游植物产生的有机物质中有很大一部分从水面下沉到深海，在那里它与大气隔绝了数百年，甚至数千年。病毒在水生环境中丰富的发现，以及许多浮游植物物种易受病毒感染的发现，表明病毒是影响水生食物网和全球化学循环的浮游植物死亡的重要来源。尽管人们对水生病毒的兴趣日益浓厚，但直接证明它们对浮游植物影响的经验数据极为有限。因此，我的研究计划的长期目标是产生关于病毒的定量信息，这些信息可以纳入浮游植物生态学的详细模型。反过来，这些信息可以用来指导环境政策，因为管理战略往往以食物网的基础为目标。例如，如果建模工作表明病毒会干扰控制有害藻华的尝试，就可以避免昂贵而无效的策略。为了实现我的长期目标，我的研究将集中在三个短期项目上，这些项目建立在我过去在水生分子生态学方面的成功基础上。这些包括：1)确定病毒对浮游植物死亡率的相对重要性，2)确定水生环境中病毒破坏的速率，以及3)检查藻类病毒-宿主系统的耦合动力学。总体而言，我的研究包括水生微生物分子技术的发展，并将通过发现病毒在水生生态系统中的重要性和影响，通过增强浮游植物生态模型，增加我们对生物地球化学循环的理解。

As the major primary producers in aquatic environments, phytoplankton play a fundamental role in aquatic food webs and influence global chemical cycles. Besides nourishing the vast majority of aquatic life, phytoplankton remove carbon dioxide from the atmosphere by converting it into organic carbon; a significant portion of the organic material produced by marine phytoplankton sinks out of the surface waters into the deep ocean where it remains isolated from the atmosphere for hundreds, or thousands of years. The discovery that viruses are abundant in aquatic environments, and that many phytoplankton species are susceptible to virus infection demonstrated that viruses are an important source of phytoplankton mortality that influence aquatic food webs and global chemical cycles. Despite the growing interest in aquatic viruses, empirical data directly demonstrating their effects on phytoplankton is extremely limited. Therefore, the long-term objective of my research program is to generate quantitative information on viruses that can be incorporated into detailed models of phytoplankton ecology. In turn, this information could be used to guide environmental policies since management strategies often target the base of food webs. For example, costly, ineffective strategies could be avoided if modelling efforts demonstrated that viruses would confound attempts to control nuisance algal blooms. To work towards my long-term objectives, my research will focus on three short-term projects that build upon my past successes in aquatic molecular ecology. These include: 1) determining the relative importance of viruses to phytoplankton mortality, 2) determining rates of virus destruction in aquatic environments, and 3) examining the coupled dynamics of algal virus-host systems. Overall, my research includes the development of molecular technologies for aquatic microbiology, and will increase our understanding of biogeochemical cycles by enhancing models of phytoplankton ecology with discoveries related to the importance and effects of viruses in aquatic ecosystems.